Forced circulation water-cooled door



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Attorneys United States Patent O F 3,155,030 FRCED CIRCULATION WATER-CULED DSOR @tte/in L. rauh, littshurgh, Pa., assigner to Reliance Steel Products Company, MeKeesport, Pa., a corporation of Pennsylvania Filed Get. 2, 1961, Ser. No. 142,276 1 Claim. (Cl. 122-48) This invention relates to a forced circulation, watercooled furnace door, and, more particularly, to a forced circulation water-cooled door having a refractory lining on the face of the door which is exposed directly to the furnace combustion chamber.

Water-cooled open-hearth furnace doors yare typically formed of spaced inner and outer plates forming between them a water circulating chamber. The edges of the plates are turned inwardly with their extremities being joined to provide a hollow marginal flange around the inner face of the door. The marginal edge of the inner plate is usually turned to an angle of greater than 90 to the plane of the plate, so that the rim of the flange overhangs the inner face of the door. The inner face of the door is covered with a refractory facing that is cast -in situ and which is retained in place by the overhanging marginal flange. This, however, is not adequate to retain the refractory for long periods of time and various kinds of studs and projections have been used on lthe inner face of the door to provide additional keys to retain the refractory in place. A cooling water supply pipe passes through the top of the door near one corner and a water outlet is provided at the top of the door near the other corner.

It has even been proposed to use keys or Studs of a hollow character to retain the refractory in place, these opening intothe water chamber between the two plates. However, as heretofore constructed, the water cooling of the keys depended on convective circulation to cool the keys. This at best was sluggish, since the water became highly heated over the entire area of the door and conditions were not conducive to good gravity circulation. The formation of steam in the keying elements yas might occur from ineffective circulation reduced the cooling of the keys, resulting in a less than hoped for life of the refractory and the possible burning off of the keys.

The present invention provides a door having hollow refractory retaining keying elements with water circulating conduits constructed within the door so arranged that the cold incoming water is forced under pressure through the keys, and from the keys then enters the main water chamber between the plates.

It is la principal object of the present invention to provide a system for force circulating continuously a coolant into Contact with the metal surfaces of a door which are contiguous with a refractory lining.

Another object is to provide a door having a forced circulation cooling system with a refractory lining anchored by tubes to the door.

A further object is the provision of a door cooled by water under pressure fed continuously through a duct system which adds structural rigidity to the door.

A complete understanding of the invention may be had from the following detailed description of a specific embodiment thereof when read in conjunction with the appended drawings, wherein:

FIG. 1 is a view of the door inner face in elevation showing only the metal members of the door;

FIG. 2 is a sectional view of the door taken along the vertical centerline II-II of FIG. 1 with refractory material shown in place on the metal members;

FIG. 3 is an enlarged sectional View of a portion of the door taken along the line Ill-III of FIG. 1 with Patented Nov. 3, 1964 refractory material applied to the door inner face; and

FIG. 4 illustrates a water inlet pipe and a conduit in an enlarged sectional View taken along line lV--IV of FIG. 1.

Referring to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is showni n FIG. l, which illustrates a preferred embodiment, a furnace panel door 11 having `a water jacket or chamber 12 and channels 13 Vfixed to an inner plate 14 .in vertically spaced relation. U-shaped tubes 15 are sealingly connected at their ends 16 to the inner plate 14, and communicate with the channels 13 via apertures 17 through the inner plate. The other ends 18 of the tubs 15 open into the chamber 12 through ports 19 provided through the inner plate.

The tubes 15 are of a configuration, such as a U-shape, so as to place their lengths in a cavity or re-entrant recess 21, which is defined by a peripheral flange 22 on the inner plate 14 directed rearwardly, inwardly and then outwardly to be sealed by suitable means such as welding to a rearwardly directed flange 23 of the outer plate 24.

It is apparent that the door structure described so far is of conventional construction with the exception of the channels 13 `and the U-shaped tubes 15 communicating the channels with the jacket 12.

As is known in the art, the tubes 15 serve as anchors for the fixing of a refractory lining 25 on the watercooled inner plate 14, and are generally embedded in the refractory which is applied in a plastic state for hardening in situ. In any event, it is imperative that the tubes and inner plate of the door cool the refractory material engaged therewith to a degree suflicient to prevent spalling of the refractory material from the contact surfaces of the metal. As above noted, doors heretofore failed to cool sufficiently the metal surfaces which were in contact with the refractory lining thus causing the deleterious effect of spalling of the refractory lining from hot spots on the metal inner plate, and the life of these doors was accordingly shortened. The coolant, or water, was wholly contained within the known doors and circulated only between a chamber and the anchor tubes'. inasmuch as the intense heat of the furnace rapidly raised the temperature of the water contained in the tubes and chamber, its cooling effect was lost.

The present invention provides a forced circulation coolant system which includes a water inlet coupling 2o which is connected to the outer plate flange 23 and to which is flow-connected an inlet pipe 27 extending in that portion of the water chamber 12 formed by the continuous, spaced flanges 22 land 23. The inlet pipe is closed at its end 2S, preferably. As shown in FIG. 4, the inlet pipe 27 communicates through conduits 29 with channels 13, the corresponding ends 31 of which protruding over the flange portion of the chamber and are closed to the chamber so as to receive water only from the conduits 29. The other ends 32 of the channels 13 are also closed in order that water may be directed only through the channels 13 to the tubes 15 via apertures 17 in the inner plate 14. The channels, therefore, serve not only as structural braces to make the inner plate rigid, but also are utilized as Water conductors.

The tubes 15 are oriented on the inner plate 14 to lie at an acute angle to the channels 13 in the direction of flow of the water force fed through the channels.

A pcephole 33 of conventional design, which extends through the door for furnace inspection, interrupts the continuity of one of the channels 13. Accordingly, two axially-aligned channels 34 and 35 are spaced on either side of the peephole. The channel 34 is connected to the inlet pipe 27 in the same manner above-described in regard to the connection of channels 13. The channel 35,

which is remote from the pipe 27, is in communication with an adjacent channel 13 via a connector 36. Likewise, the anchor tubes 15 are connected to the channels 34 and 35, and the chamber 12 in the manner abovedescribed.

An outlet coupling 37 is provided on the flange 23 of the front plate 24 in communication. with the chamber 12, and suitable clean-out openings 3S are provided near the bottom on each side of the door. Lining inspection ports 39, cable lugs 41, and a lifting yoke 4Z are suitably arranged on the door.

The forced circulation water-cooled door functions in the following manner. The door 111` is manipulated by the yoke 42 into position on a furnace, such as an openhearth furnace, after first connecting the inlet coupling 26 with a source of water under pressure, and the outlet 37 to a station remote from the door. The refractory lining 25 on the door inner plate 14 is exposed directly to the intense heat or" the furnace when the door is in this position, causing the metal of the anchor tubes 15 and inner plate 14 to become hot as a result of the heat energy transmitted through the lining.

Cold water under pressure is force fed continuously through the inlet pipe 27 and conduits Z9, to the channels 13, 34 and 35. From the channels the cold water is forced through the anchor tubes 15 and into the chamber 12. The Water within the chamber is forced through the outlet coupling 37 to a remote station where it may be passed through a heat exchanger, for example, and pumped under pressure through the door in a closed loop cycle, if desired.

It is readily appreciated that the circulation of the cooling water can be regulated such that the metal-torefractory contact areas may be maintained at a constant low temperature in proportion to the heat of the furnace, whereas heretofore such an achievement was impossible because of the inadequacy of cooling systems wherein water was circulated solely within the coniines of the door structure.

Manitestly, the above-described embodiment of the invention is merely illustrative and many modifications may be made within the spirit and scope of the invention.

What is claimed is:

A water-cooled open-hearth furnace door with a top, bottom and sides and having inner and outer faces, said door comprising an inner plate and an outer plate in lixed spaced relation, each plate having a peripheral inwardly-extending flange spaced from the other and joined at its edge to the other to hold the plates in spaced rela-1 tion and provide a jacket between the plates with a hollow flange around the inner face of the inner plate, a plurality of tubes projecting from the inner plate into the area surrounded by said hollow ange and providing means for retaining refractory over the inner plate in the area surrounded by the hollow flange, each of said tubes having one open end passing through the inner plate to the jacket, a plurality of closed water conducting structural channels on that face of the inner plate which confronts the outer` plate, the other end of each tube terminating in one of said water conducting channels, a water inlet pipe, connections from said pipe and opening into one end of each of the several channels for conducting water from the inlet pipe to the channels, and an outlet pipe leading from the space between the plates whereby water is introduced from the inlet pipe, through the connections and channels, the tubes, jacket, and the outlet pipe in the order named.

References Cited in the tile ot this patent UNITED STATES PATENTS 1,211,884 Schmidt Ian. 9, 1917 1,836,784 Williams Dec. 15, 1931 2,547,204 Groetzinger Apr. 3, 1951 2,864,345 Reighart Dec. 16, 1958 3,019,775 Robinson Feb. 6, 1962 FOREIGN PATENTS 949,954 Germany Sept. 27, 1956 

